Help - Cant connext linksys 300n and 4400n access point

First of all, i am not as computer savvy as many of you and i need a little help. The guy who originally set up my wireless networking is out of town.
First off, i have a linksys 300n router; i am trying to connect a linksys 4400n access point about 200 ft away. The guy that set up the system had to broadcast the signal in two directions, (one way using G and the other for me using N), so he changed the ip address and set it up so it works fine. The problem was the signal where i was located, wasnt strong at all. So i went out and bought a wirless-n card for my laptop. The linksys card i bought could not detect the signal at all but the wireless card in my Dell could, just not very well. So i bought the access point and attempted to set it up but didnt get too far.

So my problem is being able to get the access point to connect to the router.
I was able to log into the AP setup and tinker a little but wasnt sure of how to set it up. I also may, if i can, switch it to act like of a repeater (if that will strengthen the signal even more).

The router IP is 192.168.2.1 .....Do i use this as the Default gateway (on the AP)?
The Ip i gave to the access point is 192.168.1.245 (the default)
Subnet 255.255.255.0
should i make the router and the access point have the same DNS server?

Not sure what to do. Any info would be nice, because i really am not to sure what i am doing. Thanks